Expediting and safeguarding railway traffic.



H. A. THOMPSON.

EXPEDITING AND SAFEGUARDING RAILWAY TRAFFIC. APPLICATION FILED JAN. 27, 1915.

l 1. 85fl2 Patented May 30, 1916.

2 SHEETS-SHEET 1.

H Y A?" V A 2 Mud $96, 3

H. A. THOMPSON.

EXPEDITIN G AND SAFEGUARDING RAILWAY TRAFFIC.

APPLICATION FILED JAN-27,1915. 1,15.,@%. Patented May 30, 1916.

2 SHEETS-SHEET 2- THE COLUMBIA I'LANOGRAPH c0.. WASHINGTON, D. c.

EXPEDITING AND SAFEGUARDING RAILWAY TRAFFIC.

1,185Al2t.

Specification of Letters Patent.

Patented May 30, 191$.

Application filed January 27, 1915. Serial No. 4,654.

To all whom it may concern:

Be it known that I, HENRY ARTHUR THOMPSON, subject of the King of Great Britain and Ireland, and resident of VVithington, Manchester, in the county of Lancaster, England, have invented certain new and useful Improvements for Expediting and Safeguarding Railway Traffic, of which the following is a specification.

My invention relates to direct or indirect control of line signals, or of signaling appliances by trains and to the provision of means for enabling signalmen to watch the progress of trains which are out of sight through fog or physical obstruction.

The object of my invention is therefore the safeguarding and expediting of railway trafiic and its chief advantages are that rail bonding is practically done away with, and that long lengths of track may be controlled.

A further advantage is that main line signals may be controlled from sidings, branch lines, or the like.

My invention is particularly adapted for use with electrical power signaling, that is to say, for the direct control of light signal levers.

The presence of a train in a section or controlled portion of the track is indicated in the signal box by the absence of an indicator light, while a section unoccupied is shown by the glowing of a green lamp. The progress of a train through a section is announced by the glowing of lamps of various colors.

It is necessary in order that the full scope of my system may be attained that the metal periphery of some of the wheels of each vehicle should be metallically connected with the relative axles. Such connection however is not essential for the control of the semaphores. I propose to described a method whereby electro-magnetic devices may either control the signal levers directly (as is pos sible in the electrical operation of semaphores) or may control signal levers and semaphores indirectly. The electro-magnetic devices in my invention are actuated by automatically varying the resistance in a circuit in the manner hereinafter described.

In order that my said invention may be understood I append hereunto two sheets of drawings in which,

Figure 1 shows the wiring and Fig. 2 the cut-out signal box and track device, whllc conductor is connected to a rail length R 3 on the track, such rail length being insu- 'ated from the adjacent rail lengths and from the track; or two or more rail lengths nay be bonded together if the vehicles are very long and the rail lengths short. Or 1 again several rail lengths may be bonded together in order that a warning bell or lamp may be actuated in the signal-box for a sufficient length of time if it be impracticable to render the wheels of the coaches conductive. A short circuit between one rail and the opposite rail should be constantly maintained through one or more axles during the passage of the train over the insulated rail length in order that the full benefit of my invention may be obtained. The insulated rail length R and the opposite rail R are connected by a branch wire in series with a bridging coil H of high resistance. (I use the term high resistance merely to distinguish from the low resistances herein referred to. As a matter of fact the high resistance may not exceed 100 ohms). The uninsulated rail R is then earthed as its resistance would vary with the weather owing to the dirty joints and at times would not conduct at all. A good earth is therefore essential. A return wire must be used instead of the earth where more than one length of track is controlled from the same battery, and the opposite rail must also be insulated for the same distance as its neighbor. As a general rule a return wire would be used. At the remote end of the section or controlled portion of the track a similar arrangement obtains. It is immaterial which rail is insulated provided the opposite ra1l is earthed. A second insulated wire B remote insulated length to the same signal box,

the battery, and

leading from the R is carried back where it is conne ted to vmay also enter the signal box adjacent to the remote insulated length R? in order that an indicator ()IYdtlll suitable device may be actuated therein for observation or looking purposes. In the resultant circuit, which I ternthe black circuit to' facilitate detached to the armature 'is a light red 2 which sc'ri'pti on, is an electro-magnetic cut-out device Fig. 2 Whose coils are of low resistance. Betweensuch coils is a high resistance coil :H -*eqii'al in value to the resistance of one Atof the said device on rising with the armature causes. two springs 3 and l to otthe bridging coils on the track.

'make contact and thus to short circuit'tl e high resistance coil H I'myself tothe use of this particular kind of' I cut'roufi'devicej I do not restrict n Also in the black circuit re the ,bla'ck coils of the two low resistances functions of which aret'o control the signal sulated rail R and R before stated. In the black resistance timing-lamp 5 levers either'directly or indirectly as hereincircuit 1S LL loW sistance whosefunction is to'glow or ring during the passage or the train over the in- In the same circuit is, alsoa switch X operative by'the device In Fi g.: lthe device in question is'tlie sigthe necessary broken. It is riety of ways. My invention simply shows Show two holding magnets may be energizer. a and deenergized for thepurpose'of direct or indirect signal control. In the circuit of the said switcliat safetypositio is a red ftheswitch at danger is agreenlanip 7 of low res stance.

lamp 6"oflow resistance] In the circuit of In the white circuit are the whitevcoilsio'f the two doubly-Wound electro-magnets S and D WllOSHfllIlCtlOIl as aforesaid is.to control the signal "levers or semaphores. Alsoin the white circuit is'a fresistance coil '8 by means of which the I j strengthof the current in such circuit is fixed.

Also in the white circuiti s an indicator lamp 9 or the like Whose function. is to show that ;the. white ,circuit is not disconnected' aiid j flows fcontinuously through the white "circuit ener 'iZin the doubl -wound electro- H, b C) l 1 magnets S and D; the direction of the low j of such current around the cores being opposite totl'iedirection in h chthe current in the black circuit .fiows around them. Norn ally a comparatively Weakeurrent flows through the black circuit there being in 1 such circuit the three high resistances, the

resistance of the line wire, the two low resistance coils of the electroiiiagnetic cut- 1 1 fout andthe black coils of the other -twoeleotro-magnets as Well as the resistance doubly wound electrd-magnets S and D the I g bridging resistance H or vbell of low re- I the black circuit being new "coils of electro-magnet S are high resistance H in the signal box still bei suitable device'to the poles of such electromagnet, the said device in turn preventing the lever from flying back to danger. In

Fig. 1 the lower end of an iron signal lever is held by a single core GlQCtlO-l11z1gl1Gt S but 1 it is to be clearly understood that the holding electro-niagnets may be of any suitable type and that they may control a shoe or any secondary mechanical or electrical device capable of effecting the necessary purpose. lVhen the wheels of the engine reach the short insulated length of rail R the is short-circuited,

the current flowing from one rail through the axles and the wheels to the other rail.

The current in the black coil of the electroniagnet S is now i'ei dered equal in value to that in the white coil of the same electromagnet and the red lamp 6 glows and the signal lever would be released, or would be capable of being released by the Signalman.

"but for the fact that the clectro-inagnetic cut-out is actuated by the strengthened current in the black circuit. The high resistance between the two coils of the cut-cut device is cut out of the black circuit and the signal lever is still held, the current in stronger than that in the white circuit. Further the timin'g lamp 5 which until the two high resistances are simultaneously cut out glows but feebly now glows brightly and continues to insulated rail length. I assume that a sumcientnumber of wheels and axles are rendo so until the whole train has cleared the dered conductive otherwise the semaphore would be restored as soon as the engine and tender cleared the-insulated rail length. It

' only the wheels and axles oi the engine and tender are conductive the rule forbidding the restoration of the signal until the pasfthat the battery is not run down. A current sage of the whole train past such signal tingency I consider in mvinvention. hen

' the last vehiclehas cleared the insulated rail length the currents inthe white and black equalized (the ing cut out) and the said currents opposing each other the magnetic effect is ml: and the signal lever fiies back to danger. The black circuit s momentarilydisconnected and the signal box high resistance is again brought into the black circuit, with the result that the current in the white coil of electro-magnet D is only opposed by the weak current in the black circuit. The signal lever or controlling device is thus held at danger. The process is repeated at the remote end of the controlled portion of the track, the signallever controlling the restored signal at the entrance of such portion not yet however being capable of movement. The timing lamp 5 glows during the passage of the train over the second insulated rail length as also does the green lamp 7. The high resistance in the signal box being again cut out, the green lamp continues to glow when the train has completely cleared the section and the currents in the white and black coils of electro-magnet D being equal in strength and opposite in direction allow the signal lever to be pulled forward when required.

Fig. 1 shows the inner segment 10 of the signal lever switch connecting two outer segments 11 and 12. In the danger position the two other outer segments 13 and 14., would be connected instead.

Intermediate places may be brought under observation in a similar manner to that described without interference with the signals. A suitable length of rail R is insulated as before. The insulated length is connected with one pole of the battery in series with say a purple lamp or a bell or both in the signal box. The opposite rail is also insulated for the same distance and connected to the other pole of the battery. When a train passes over the inter mediate length the high resistance H between the rails is shert-circuited and the lamp 15 glows or a bell. rings; or both a amp and a bell are actuated. If desired two lamps may be used, one operative by the normal current and the other by the strengthened current due to the passage of the train.

My invention may be used for lock and bloc working or for the control of signaling appliances generally.

it may, if required, include in the black and 'white circuits doubly-wound electromagnets inseries with S and D to control the semaphores as well as the signal levers on exactly the same principle. I may use my system to control the semaphores only, the electro-magnets S and D holding the semaphores directly or relaying currents or breaking circuits in any manner whatsoever, the said electro-magnets being placed in any suitable place provided the coils are in the black and white circuits respectively. lThe switch controlling the black circuit may be mechanically actuated by the semaphore itself.

It is evident that if the black circuit contain an additional high resistance or bridging coil and that if th1s resistance be cut out of the said circuit an alteration in the current strength therein will be effected. I propose therefore to use a third bridging coil, to increase the voltage of the battery, and to insulate portions of each rail to effect the following purpose. If a controlled section contains a siding or branch line it is obvious that a train entering such side road would fail, under the conditions hereinbefore prescribed, to actuate a second time the electro-magnetic cut-out whose final function is to cause the green lamp to glow and to allow the signal-lever to be pulled to safety. But it is imperative that this result should be attained as soon as the train is well inside the siding or branch road. By using a return wire and a third bridging coil it is accomplished as follows :-Fig. 3 shows in a simple manner the black circuit modified to suit the circumstances, the signal boX details being omitted. A third bridging coil H is placed in series with H and H at the entrance to the siding or branch line (or well inside especially if it be impracticable to render the wheels of the coaches conductive). It is clear that the necessary alteration in the value of the current will be effected whether the train enters the siding or branch line or whether it proceeds to the end of the controlled portion of the main line since the bridging coil H relative to the siding and the bridging coil H relative to the remote end of the main line section are in series with each other.

I may use any possible number of bridging coils on the tracks in order that I may deal successfully with complicated junctions and the like, no alteration in the method of controlling signals being contemplated.

If the lamps used in my invention are of low resistance the change in the resistance of the circuit due to the incandescence of the filaments will not affect the working of my invention if the strength of the current in the white circuit be adjusted to the resistance of the black circuit while the red or green lamps are glowing. The variation in resistance of the timing lamp need not be taken into account. I add the following observations on the working of my invention:-If the cut-out fails to respond to the increased current the signal will fly back to danger when the train enters the section. If the failure occurs when the train leaves the section the green lamp will not glow after the passage of the train and the signal lever cannot be pulled to safety. If the battery current fails the signal lever will fly back to danger and no light will glow (the indication of train in section). If the white circuit bev disconnected while the signal is at danger the lever might be pulled to safety with an effort if the control be direct while a train is in the section but the failure of the glow lamp 9 inserted in the lamp cannot glow.

Ordinary mechanical or electrical interlocking completes the chain of safety. It is evident that with so much resistance in circuit a battery of fairly high voltage must be used.

In calculating the resistance of the bridging coils it is necessary to aim at as great an increase as possible upon the normal current passing through the black circuit, such increase being consequent upon the cutting out of one of the high resistances. It is the 20v difference between the normal and the strengthened current in such circuit which governs the strength of the current in the white circuit the function of the latter current as aforesaid, being to hold the signal lever, semaphore, or controlling device. The

"magneto-motive force of the electro-magnetsandthe amount of current required for the lamps must also be considered. I may relay separate currents for the lamps but this is obviously undesirable. 'The armature of the cut-out device is preferably gravity controlled. I may use indicators other than lamps or may dispense with indicators altogether, 7

Where freight wagons having metal wheels are included in a passenger train such vehicles should be placed immediately behind the tender unless the wheels of all vehicles are rendered conductive. If only the wheels of freight trains are conductive it will be observed that my invention will serve to distinguish between freight and passenger trains. V

-VVhat I claim as my invention and desire to secure by Letters'Patent is 1. In a railway signal control system the combination of a length of railway track having an insulatedportionat each end thereof, a resistance connecting each insulated length of rail with the opposite rail each of such resistances being contained in a circuit of variable resistance, a plurality of locking electro-magnets'each having. opposing *indings a winding of each of said electro-magnets being contained in the said circuit of variable resistance; such combination being so characterized that a train passing over either of said insulated portions short-circuits the resistance between said rails and causes an increase in the current strength'in the said circuit of variable re sistance anda diminution in the strength of the magnetism in said electro-magnet's.

2. In a railway signal control system the combination ofa' length of railway track having an insulated portion at each end thereof, a resistance connecting each insulated length of rail with the opposite rail each of such resistances being contained in a. circuit of variable resistance, a plurality of locking electro-magnets each having opposing windings a winding of each of said electro-magnets being contained in the said circuit of variable resistance, a cut-out relay in said circuit; such combination being so characterized that a train passing over said insulated portions of track short-circuits resistance in the said circuit of variable resistance and strengthens the current therein, thereby actuating said relay and causing an additional resistance to be eliminated from said circuit.

3. In a railway signal control system the combination of a length of railway track having an insulated portion at each end thereof, a resistance connecting each insulated length of rail with the opposite rail each of such resistances being contained in a circuit of variable resistance, a plurality of locking electro-magnets each having opposing windings a winding of each of said electro-magnets being contained in the said circuit of variable resistance, a cut-out relay in said circuit controlling a resistance therein; such combination being so characterized that, said cut-out relay having been actuated by the 'short-circuiting through a trains wheels and axles of resistance between the rails, said locking electro-magnets are no longer able to retain an armature when said having an insulated portion at each end thereof, a resistance connecting each insulated length of rail with the opposite rail each of such resistances being contained in a circuit of variable resistance, a plurality of locking electro-magnets each having opposing windings a winding of each of said electro-magnets being contained in the said circuit of variable resistance, a cutout relay in said circuit controlling a resistance'therein, a plurality of indicators in the said circuit of variable resistance; such combination being so characterized that said cut-out relay being actuated by the passage of a train over an insulated portion of track said indicators are operated by the consequent increase in the current in the said circuit of variable resistance.

5. In a railway signal control system the combination of a plurality of railway tracks, a plurality of insulated lengths of track, a resistance coil connecting each insulated length of rail with the opposite rail each of such rails being contained in a circuit of variable resistance, a plu 'ality of locking electro-magnets each having two opposing windings one of each of such windings being contained in the said circuit of variable resistance and the other of such windings in a circuit of invariable resistance, a cut-out relay in the said circuit of variable resistance and controlling a resistance therein; such combination being so characterized that a train short-circuiting one of said resistances between the rails increases the strength of a current in the said circuit of variable resistance, actuates said relay, and varies the strength of the magnetism in said locking electro-magnets.

6. In a railway signal control system the combination of a length of railway track having an insulated portion at each end thereof; a circuit of variable resistance containing a resistance coil bridging each insulated length of rail with the opposite rail and also containing the magnetizing coils of a cut-out relay acting on resistance in said circuit and also containing coils appertaining to two locking electro-magnets; a circuit of invariable resistance containing a regulating resistance, and coils appertaining to said locking electro-magnets; such combination being so characterized that the currents in the two said circuits induce opposing magnetisms in each of said locking electro-magnets.

In testimony whereof I have hereunto set my hand in the presence of two Witnesses. HENRY ARTHUR THOMPSON.

Witnesses:

WILLIAM H. TAYLOR, AMY E. EVINs.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. G. 

